random.sml

local
    fun rmod x y = x - y * Real.realFloor (x / y);
    val a = 16807.0;
    val m = 2147483647.0;
    val random_seed = ref 1.0;
in
    fun random () =
    let
        val r = rmod (a * ! random_seed) m
    in
        random_seed := r;
        Real.floor r
    end
end;